Improved sandwich enzyme-linked immunosorbent assays for transforming growth factor beta 1.

Transforming growth factor beta s (TGF-beta s), a highly homologous family of 25 kDa dimers, function as both paracrine and autocrine growth modulators which relay a broad spectrum of critical biological functions. Although sensitive bioassays for TGF-beta s have been described, their interference by other growth modulators have limited their application. We have previously described a highly sensitive (20-50 pg/ml) and specific sandwich enzyme-linked immunosorbent assay (SELISA) for TGF-beta 1, based on use of rabbit anti-TGF-beta 1 as the capture antibody. Widespread use of this assay was limited by the availability of this rather low-titer antibody. This report describes improved TGF-beta 1 SELISAs with comparable sensitivities to the above assay based on available sources of commercial monoclonal and polyclonal antibodies. These newly developed SELISAs are the most sensitive, specific, precise and convenient methods for the quantitation of TGF-beta 1 in complex biological fluids.